Atypical discrete papular lichen myxedematosus associated with monoclonal gammopathy: Report of four cases and review of the literature

Background: Discrete papular lichen myxedematosus (DPLM) is a rare form of localized lichen myxedematosus that presents with skin involvement only and without systemic involvement. Object: To describe our experience with atypical cases of DPLM associated with monoclonal gammopathy. Methods: Data were collected from patients with clinicopathological evidence of DPLM associated with monoclonal gammopathy who presented to the Department of Dermatology of two tertiary university-affiliated medical centres from 2000 to 2015 and were followed prospectively. Results: The sample included four patients (three males) with a mean age of 58 years. No clinicopathological differences from typical cases of DPLM were observed, except for the presence of monoclonal gammopathy. The patients were followed up for a mean of 34 months (6-72 months) and no progression to scleromyxedema, multiple myeloma or systemic involvement was observed. No therapy was applied, except for topical tacrolimus or steroids, and the eruptions remained stable. Conclusion: Our experience indicates an excellent prognosis of DPLM even for atypical cases in spite of the presence of monoclonal gammopathy.